Q. My dog threw up for two days....wouldn't eat but is drinking water the third day she only drank water and is starting
DAVID ELBEZE, DVM, MRCVS
A. this is a sign that no matter what she is taking in, she can't keep it. If she cannot keep fluids in she will get dehydrated very quickly without treatment.
You need to take her to the vet ASAP, she need to receive anti emetic and possibly fluids if she is dehydrated.
There are plenty of reasons for vomiting, the most common being a gastrointestinal infection and a foreign body ingestion.